<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
      div{
          width: 100px;
          height: 100px;
          background-color: red;

          position: fixed;
          right:0;
          bottom:0;
      }
    </style>
</head>
<body>
    <!-- 固定定位  将元素固定到页面上的特定位置 -->
    <div>

    </div>
</body>
</html>